The nuclear magnetic resonance spectra of the aromatic, olefinic, and hydroxyl protons of 41 flavonoids have been examined. It is found that these spectra reveal the pattern of oxygen substitution on the aromatic rings, the nature of the heterocyclic ring, and, often, the nature and arrangement of the oxygen-borne groups.

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The proton magnetic resonance spectra of various charged species from thirty-three azoles have been measured.In N-methvl-imidazoles and -1.2.4-triazoles the sites of protonation have been determined, and the cations appear to be stabilised by amidinium type resonance.THE proton magnetic resonance (p.m.r.) spectra of imidazole, pyrazole, 1,2,3-and 1,2,4-triazole, tetrazole, and certain of their derivatives have been described 1-7 but no systematic study of the spectra of these ring systems has been reported. We here discuss the spectra of neutral molecules, cations, and where possible anions, of thirty-three compounds from these series.Chemical shift data for the compounds studied, measured as neutral molecules in deuteriochloroform, as cations in trifluoroacetic acid, or as anions in 2~-sodium deuteroxide,8 are in Table 1. Assignment of peaks to specific protons in the parent compounds is readily accomplished by inspection, and for the N-methyl derivatives is made simpler by the small substituent

Two ovariectomized ewes were given a single intraruminal dose of [4-14C]- labelled isoflavone and slaughtered 6 hr later. In the ewe given [4-14C]biochanin A, labelled genistein was detected in addition to labelled biochanin A in the blood plasma, urine, kidney, liver, bile, contents of the rumen, and those of the small intestine. p-Ethylphenol, which is almost certainly a metabolite of biochanin A, was present in the urine but not labelled, which indicates that it originates from ring B of the isoflavone molecule. In the ewe given [4-14C]formononetin, a similar distribution of the isoflavone and its demethylation product, daidzein, was found. In addition, labelled equol was found in the blood plasma and urine. Another labelled metabolite, identified as O-desmethyl angolensin (2,4-dihydroxyphenyl p-hydroxy-�-methylbenzyl ketone), was also found in the urine. In the urine from both ewes, there were also labelled light petroleuminsoluble acidic compounds but they were not identified.